diff --git a/cluster/kubernetes/cached_disco_test.go b/cluster/kubernetes/cached_disco_test.go
index d7bf0a74a..6c56cb2dd 100644
--- a/cluster/kubernetes/cached_disco_test.go
+++ b/cluster/kubernetes/cached_disco_test.go
@@ -78,7 +78,7 @@ func TestCachedDiscovery(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	namespaced, err := namespacer.lookupNamespaced("foo/v1", "Custom")
+	namespaced, err := namespacer.lookupNamespaced("foo/v1", "Custom", nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -124,7 +124,7 @@ func TestCachedDiscovery(t *testing.T) {
 		t.Error("does not exist")
 	}
 
-	namespaced, err = namespacer.lookupNamespaced("foo/v1", "Custom")
+	namespaced, err = namespacer.lookupNamespaced("foo/v1", "Custom", nil)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/cluster/kubernetes/manifests.go b/cluster/kubernetes/manifests.go
index 576a09bc1..e7cb5602a 100644
--- a/cluster/kubernetes/manifests.go
+++ b/cluster/kubernetes/manifests.go
@@ -1,12 +1,19 @@
 package kubernetes
 
 import (
+	"gopkg.in/yaml.v2"
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+
 	"github.com/weaveworks/flux"
 	kresource "github.com/weaveworks/flux/cluster/kubernetes/resource"
 	"github.com/weaveworks/flux/image"
 	"github.com/weaveworks/flux/resource"
 )
 
+// ResourceScopes maps resource definitions (GroupVersionKind) to whether they are namespaced or not
+type ResourceScopes map[schema.GroupVersionKind]v1beta1.ResourceScope
+
 // namespacer assigns namespaces to manifests that need it (or "" if
 // the manifest should not have a namespace.
 type namespacer interface {
@@ -14,7 +21,7 @@ type namespacer interface {
 	// the manifest to be applied. This may be "", indicating that it
 	// should not have a namespace (i.e., it's a cluster-level
 	// resource).
-	EffectiveNamespace(kresource.KubeManifest) (string, error)
+	EffectiveNamespace(manifest kresource.KubeManifest, knownScopes ResourceScopes) (string, error)
 }
 
 // Manifests is an implementation of cluster.Manifests, particular to
@@ -26,11 +33,39 @@ type Manifests struct {
 	Namespacer namespacer
 }
 
+func getCRDScopes(manifests map[string]kresource.KubeManifest) ResourceScopes {
+	result := ResourceScopes{}
+	for _, km := range manifests {
+		if km.GetKind() == "CustomResourceDefinition" {
+			var crd v1beta1.CustomResourceDefinition
+			if err := yaml.Unmarshal(km.Bytes(), &crd); err != nil {
+				// The CRD can't be parsed, so we (intentionally) ignore it and
+				// just hope for EffectiveNamespace() to find its scope in the cluster if needed.
+				continue
+			}
+			crdVersions := crd.Spec.Versions
+			if len(crdVersions) == 0 {
+				crdVersions = []v1beta1.CustomResourceDefinitionVersion{{Name: crd.Spec.Version}}
+			}
+			for _, crdVersion := range crdVersions {
+				gvk := schema.GroupVersionKind{
+					Group:   crd.Spec.Group,
+					Version: crdVersion.Name,
+					Kind:    crd.Spec.Names.Kind,
+				}
+				result[gvk] = crd.Spec.Scope
+			}
+		}
+	}
+	return result
+}
+
 func postProcess(manifests map[string]kresource.KubeManifest, nser namespacer) (map[string]resource.Resource, error) {
+	knownScopes := getCRDScopes(manifests)
 	result := map[string]resource.Resource{}
 	for _, km := range manifests {
 		if nser != nil {
-			ns, err := nser.EffectiveNamespace(km)
+			ns, err := nser.EffectiveNamespace(km, knownScopes)
 			if err != nil {
 				return nil, err
 			}
diff --git a/cluster/kubernetes/manifests_test.go b/cluster/kubernetes/manifests_test.go
new file mode 100644
index 000000000..7e4494edc
--- /dev/null
+++ b/cluster/kubernetes/manifests_test.go
@@ -0,0 +1,62 @@
+package kubernetes
+
+import (
+	"io/ioutil"
+	"path/filepath"
+	"testing"
+
+	"github.com/weaveworks/flux/cluster/kubernetes/testfiles"
+)
+
+func TestKnownCRDScope(t *testing.T) {
+	coreClient := makeFakeClient()
+
+	nser, err := NewNamespacer(coreClient.Discovery())
+	if err != nil {
+		t.Fatal(err)
+	}
+	manifests := Manifests{nser}
+
+	dir, cleanup := testfiles.TempDir(t)
+	defer cleanup()
+	const defs = `---
+apiVersion: apiextensions.k8s.io/v1beta1
+kind: CustomResourceDefinition
+metadata:
+  name: foo
+spec:
+  group: foo.example.com
+  names:
+    kind: Foo
+    listKind: FooList
+    plural: foos
+    shortNames:
+    - foo
+  scope: Namespaced
+  version: v1beta1
+  versions:
+    - name: v1beta1
+      served: true
+      storage: true
+---
+apiVersion: foo.example.com/v1beta1
+kind: Foo
+metadata:
+  name: fooinstance
+  namespace: bar
+`
+
+	if err = ioutil.WriteFile(filepath.Join(dir, "test.yaml"), []byte(defs), 0600); err != nil {
+		t.Fatal(err)
+	}
+
+	resources, err := manifests.LoadManifests(dir, []string{dir})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, ok := resources["bar:foo/fooinstance"]; !ok {
+		t.Fatal("couldn't find crd instance")
+	}
+
+}
diff --git a/cluster/kubernetes/namespacer.go b/cluster/kubernetes/namespacer.go
index 8386e7425..d2f9e06a9 100644
--- a/cluster/kubernetes/namespacer.go
+++ b/cluster/kubernetes/namespacer.go
@@ -3,6 +3,8 @@ package kubernetes
 import (
 	"fmt"
 
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/tools/clientcmd"
 
@@ -55,8 +57,8 @@ var getDefaultNamespace = func() (string, error) {
 // effectiveNamespace yields the namespace that would be used for this
 // resource were it applied, taking into account the kind of the
 // resource, and local configuration.
-func (n *namespaceViaDiscovery) EffectiveNamespace(m kresource.KubeManifest) (string, error) {
-	namespaced, err := n.lookupNamespaced(m.GroupVersion(), m.GetKind())
+func (n *namespaceViaDiscovery) EffectiveNamespace(m kresource.KubeManifest, knownScopes ResourceScopes) (string, error) {
+	namespaced, err := n.lookupNamespaced(m.GroupVersion(), m.GetKind(), knownScopes)
 	switch {
 	case err != nil:
 		return "", err
@@ -68,7 +70,24 @@ func (n *namespaceViaDiscovery) EffectiveNamespace(m kresource.KubeManifest) (st
 	return m.GetNamespace(), nil
 }
 
-func (n *namespaceViaDiscovery) lookupNamespaced(groupVersion, kind string) (bool, error) {
+func (n *namespaceViaDiscovery) lookupNamespaced(groupVersion string, kind string, knownScopes ResourceScopes) (bool, error) {
+	namespaced, clusterErr := n.lookupNamespacedInCluster(groupVersion, kind)
+	if clusterErr == nil || knownScopes == nil {
+		return namespaced, nil
+	}
+	// Not found in the cluster, let's try the known scopes
+	gv, err := schema.ParseGroupVersion(groupVersion)
+	if err != nil {
+		return false, clusterErr
+	}
+	scope, found := knownScopes[gv.WithKind(kind)]
+	if !found {
+		return false, clusterErr
+	}
+	return scope == v1beta1.NamespaceScoped, nil
+}
+
+func (n *namespaceViaDiscovery) lookupNamespacedInCluster(groupVersion, kind string) (bool, error) {
 	resourceList, err := n.disco.ServerResourcesForGroupVersion(groupVersion)
 	if err != nil {
 		return false, fmt.Errorf("error looking up API resources for %s.%s: %s", kind, groupVersion, err.Error())
diff --git a/cluster/kubernetes/namespacer_test.go b/cluster/kubernetes/namespacer_test.go
index 6a1a97476..95871a5c4 100644
--- a/cluster/kubernetes/namespacer_test.go
+++ b/cluster/kubernetes/namespacer_test.go
@@ -27,6 +27,12 @@ func makeFakeClient() *corefake.Clientset {
 				{Name: "namespaces", SingularName: "namespace", Namespaced: false, Kind: "Namespace", Verbs: getAndList},
 			},
 		},
+		{
+			GroupVersion: "apiextensions.k8s.io/v1beta1",
+			APIResources: []metav1.APIResource{
+				{Name: "customresourcedefinitions", SingularName: "customresourcedefinition", Namespaced: false, Kind: "CustomResourceDefinition", Verbs: getAndList},
+			},
+		},
 	}
 
 	coreClient := corefake.NewSimpleClientset()
@@ -101,7 +107,7 @@ metadata:
 			t.Errorf("manifest for %q not found", id)
 			return
 		}
-		got, err := nser.EffectiveNamespace(res)
+		got, err := nser.EffectiveNamespace(res, nil)
 		if err != nil {
 			t.Errorf("error getting effective namespace for %q: %s", id, err.Error())
 			return
diff --git a/daemon/daemon_test.go b/daemon/daemon_test.go
index d2e040699..8e603800f 100644
--- a/daemon/daemon_test.go
+++ b/daemon/daemon_test.go
@@ -634,7 +634,7 @@ func mustParseImageRef(ref string) image.Ref {
 
 type anonNamespacer func(kresource.KubeManifest) string
 
-func (fn anonNamespacer) EffectiveNamespace(m kresource.KubeManifest) (string, error) {
+func (fn anonNamespacer) EffectiveNamespace(m kresource.KubeManifest, _ kubernetes.ResourceScopes) (string, error) {
 	return fn(m), nil
 }
 
diff --git a/release/releaser_test.go b/release/releaser_test.go
index 5a0fe5989..f90f5aae3 100644
--- a/release/releaser_test.go
+++ b/release/releaser_test.go
@@ -24,7 +24,7 @@ import (
 
 type constNamespacer string
 
-func (ns constNamespacer) EffectiveNamespace(kresource.KubeManifest) (string, error) {
+func (ns constNamespacer) EffectiveNamespace(manifest kresource.KubeManifest, _ kubernetes.ResourceScopes) (string, error) {
 	return string(ns), nil
 }